function [vP]=vectorP(maxBOs, aMinBE, aMaxBE)
  %Mean number of backoff slots waiting in BOx
  %Equation (2)

  BE=aMinBE:aMaxBE;
  if( length(BE) < maxBOs )
    BE(1:maxBOs)=[BE, BE(end)*ones(1,maxBOs-length(BE))];
  else
    BE=BE(1:maxBOs);
  end %if( length(BE)
  uDistr=(2.^BE-1)./2;
  vP=1./(uDistr+1);
end